OBJECTIVE: To investigate the relationship between commonly used radiologic parameters and occurrence of low back pain (LBP) through prospective study using pre-employment radiologic examination in high risk workplace. METHOD: One hundred and fifty four male workers in high risk workplace were evaluated. Lumbar lordosis, lumbosacral angle, lumbar gravity line and lumbar disc height-related parameters were measured using simple radiologic films of lateral lumbosacral view taken during pre-employment medical check. Relationship between occurrence of LBP during post-employment period with a mean 1.7+/-1.0 years and radiologic parameter was investigated. RESULTS: Lumbar lordosis, lumbosacral angle and lumbar disc height were not significantly correlated to the occurrence of LBP. Amount of anterior shift of lumbar gravity line did not showed correlation to occurrence of LBP, but subjects with posterior displacement of lumbar gravity line showed significantly low rate of occurrence of LBP. CONCLUSION: These results suggest that commonly used radiologic parameters are not so useful to predict occurrence of LBP in high risk workers. The possibile preventive effect of posterior shift of lumbar gravity line seems to be worth further researching.